Archives de catégorie : biology+acidification

Global Warming off the hook? Alien species are primary cause of recent global extinctions

by University College London, March 3, 2019 in WUWT


Alien species are the main driver of recent extinctions in both animals and plants, according to a new study by UCL researchers.

They found that since 1500, alien species have been solely responsible for 126 extinctions, 13% of the total number studied.

Of 953 global extinctions, 300 happened in some part because of alien species, and of those 300, 42% had alien species alone listed as the cause of their demise.

The study, published today in Frontiers in Ecology and the Environment, used data from the 2017 IUCN Red List on the total numbers of species that are considered to have gone extinct globally since 1500.

In total, 261 out of 782 animal species (33.4%) and 39 out of 153 plant species (25.5%) listed aliens as one of their extinction drivers. In contrast, native species impacts were associated with only 2.7% of animal extinctions and 4.6% of plant extinctions.

 

 

Coral Reefs in West Hawaiʽi Showing Signs of Recovery

by P. Homewood, February 21, 2019 NotaLotofPeopleKnowThat


Surveys identified 25 coral species in West Hawaiʻi. Lobe coral (Porites lobata), one of the area’s most dominant species, proved to be the most resilient—with only 50% bleaching in 2015. Cauliflower corals (Pocillopora meandrina) were hardest hit—with 98% bleaching—but recent surveys show that they are beginning to recover.

Analysis Finds Oceans Have Become LESS ‘Acidic’ With Rising CO2, Challenging The ‘Acidification’ Narrative

by K. Richard, February 14, 2019 in NoTricksZone


A modest long-term (1800s-present) declining trend in ocean pH values predominantly occurred prior to 1930, or before anthropogenic CO2 emissions began rising precipitously. Since 1930, seawater pH trends have risen slightly, meaning sharply rising CO2 has been coincident with less, not more, ocean “acidification”

 

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Image Source (lower graph): Wei et al., 2015

 

 

GWPF Call For Insect Decline Paper To Be Withdrawn

by P. Homewood, February 11, 2019 in NotaLotofPeopleKnowThat


London, 11 February: The scientific paper behind newspaper claims that insect populations were threatened with extinction was based on data known to be unreliable. That’s according to the Global Warming Policy Foundation, which today called for the paper to be withdrawn.

The paper, by US scientists Bradford C Lister and Andres Garcia, claimed that a rapid decline in insect populations in a rainforest in Puerto Rico was the result of rising temperatures. The Washington Post called the study “hyperalarming”, while the Guardian discussed climate change causing “insect collapse”.

However, the authors’ evidence that temperatures had, in fact, risen turns out to be based on a single weather station, which was known to be unreliable because of undocumented changes to equipment and location resulting in a substantial and abrupt increase in recorded temperatures in September 1992.

Since 1992, temperatures at this station have actually declined.

The Obvious Biomass Emissions Error

by Steve Goreham, February 7, 2019 in WUWT


When Thomas Edison established his Pearl Street power plant in New York City in 1892, he used coal for fuel, not wood. Wood fuel could not compete with the cost of coal in 1892 and it still can’t today. Nevertheless, burning of biomass is widely regarded as sustainable and promoted as a solution for climate change, especially in Europe.

Today, Europe produces about 17 percent of its energy and 29 percent of its electricity from renewable sources. Biomass accounts for about 19 percent of the electricity generated from renewables. Since 2000, Europe’s biomass consumption for energy production is up 84 percent.

For example, biomass fuel produced 18 percent of Denmark’s electricity in 2017. For the last two decades, Denmark has been reducing coal-fired power plant output, but adding biomass-powered plants. Since 2000, Denmark’s use of coal fuel for electricity decreased 63 percent. But the use of biomass fuel for electricity in Denmark increased by a factor of five, almost exactly replacing the decline in coal output. About three-quarters of the biomass consumed by Denmark is wood, with most of it imported.

New islands, happy feet: Study reveals island formation a key driver of penguin speciation

by Molecular Biology and Evolution (Oxford University Press), February 5, 201 in ScienceDaily


Ever since Darwin first set foot on the Galapagos, evolutionary biologists have long known that the geographic isolation of archipelogos has helped spur the formation of new species.

Now, an international research team led by Theresa Cole at the University of Otago, New Zealand, has found the same holds true for penguins. They have found the first compelling evidence that modern penguin diversity is driven by islands, despite spending the majority of their lives at sea.

“We propose that this diversification pulse was tied to the emergence of islands, which created new opportunities for isolation and speciation,” said Cole.

Over the last 5 million years, during the Miocene period, (particularly within the last 2 million years), island emergence in the Southern Hemisphere has driven several branches on the penguin evolutionary tree, and also drove the more recent influence of human-caused extinctions of two recently extinct penguin species from New Zealand’s Chatham Islands.

Study: Much of the surface ocean will shift in color by end of 21st century

by Charles the moderator,  February 5, 2019 in WUWT


Climate-driven changes in phytoplankton communities will intensify the blue and green regions of the world’s oceans

From the Massachusetts Institute of Technology

Climate change is causing significant changes to phytoplankton in the world’s oceans, and a new MIT study finds that over the coming decades these changes will affect the ocean’s color, intensifying its blue regions and its green ones. Satellites should detect these changes in hue, providing early warning of wide-scale changes to marine ecosystems.

Writing in Nature Communications, researchers report that they have developed a global model that simulates the growth and interaction of different species of phytoplankton, or algae, and how the mix of species in various locations will change as temperatures rise around the world. The researchers also simulated the way phytoplankton absorb and reflect light, and how the ocean’s color changes as global warming affects the makeup of phytoplankton communities.

The researchers ran the model through the end of the 21st century and found that, by the year 2100, more than 50 percent of the world’s oceans will shift in color, due to climate change.

Scientists identify two new species of fungi in retreating Arctic glacier

by Research Organization of Information and Systems, January 15, 2019 in ScienceDaily


Two new species of fungi have made an appearance in a rapidly melting glacier on Ellesmere Island in the Canadian Arctic, just west of Greenland. A collaborative team of researchers from Japan’s National Institute of Polar Research, The Graduate University for Advanced Studies in Tokyo, Japan, and Laval University in Québec, Canada made the discovery.

The scientists published their results on DATE in two separate papers, one for each new species, in the International Journal of Systematic and Evolutionary Microbiology.

“The knowledge of fungi inhabiting the Arctic is still fragmentary. We set out to survey the fungal diversity in the Canadian High Arctic,” said Masaharu Tsuji, a project researcher at the National Institute of Polar Research in Japan and first author on both papers. “We found two new fungal species in the same investigation on Ellesmere Island.”

Algae thrive under Greenland sea ice

by Bigelow Laboratory for Ocean Sciences, January 8, 2019 in ScicneDaily


Microscopic marine plants flourish beneath the ice that covers the Greenland Sea, according to a new study. These phytoplankton create the energy that fuels ocean ecosystems, and the study found that half of this energy is produced under the sea ice in late winter and early spring, and the other half at the edge of the ice in spring.

CORAL REEFS CAN TAKE THE HEAT, UNLIKE EXPERTS CRYING WOLF

by Peter Ridd, December 26, 2018 in GWPF


Scientists from James Cook University have just published a paper on the bleaching and death of corals on the Great Barrier Reef and were surprised that the death rate was less than they expected, because of the adaptability of corals to changing temperatures.

It appears as though they exaggerated their original claims and are quietly backtracking.

To misquote Oscar Wilde, to exaggerate once is a misfortune, to do it twice looks careless, but to do it repeatedly looks like unforgivable systemic unreliability by some of our major science organisations.

The very rapid adaptation of corals to high temperatures is a well-known phenomenon; besides, if you heat corals in a given year, they tend to be less susceptible in the future to overheating. This is why corals are one of the least likely species to be affected by climate change, irrespective of whether you believe the climate is changing by natural fluctuations or because of human influence.

Corals have a unique way of dealing with changing temperature, by changing the microscopic plants that live inside them. These microscopic plants, called zooxanthellae, give the coral energy from the sun through photosynthesis in exchange for a comfortable home inside the coral. When the water gets hot, these little plants effectively become poisonous to the coral and the coral throws them out, which turns the coral white — that is, it bleaches.

 

Ocean Acidification Background Context

by ‘Guest Blogger’, December 23, 2018 in WUWT


Obiter dictum. We acknowledge that seawater is basic and cannot truly acidify (pH<7). But that is a losing semantic quibble, not a winning skeptical argument. The generally accepted linguistic convention—for better or worse–is that lowering seawater pH means ‘acidification’. There is no doubt that adding dissolved CO2 does lower pH. The relevant questions are how much and whether that amount matters. This post answers both questions (a little, not much) without the two specific false alarms that motivated the ebook version.

There are certainly some ocean related AGW consequences beyond any scientific doubt. Henry’s Law requires that the partial pressures of atmospheric and dissolved ocean CO2equilibrate. Rising atmospheric CO2 must increase dissolved seawater CO2. That is long established simple physical chemistry.

This lowers pH by increasing carbonic acid. NOAA PMEL has documented this in the central Pacific at Station Aloha off Mauna Loa where sea surface pH has declined from 8.11 to 8.07 since 1991, as dissolved pCO2 increased from ≈325 to ≈360μatm while atmospheric CO2 increased from about 355 to 395 ppm. That is Δ0.04 pH in 24 years.

See also here (in French)

La biomasse globale : de larges incertitudes, également sur le cycle du carbone!

by Prof. Paul Berth, 14 décembre 2018 in ScienceClimatEnergie


Dans un article récent de juin 2018[1], le biologiste Yinon Bar-On et ses collaborateurs ont estimé la biomasse totale de la biosphère actuelle (Bar-On et al. 2018). Pour cela, ils ont simplement estimé les nombres de bactéries, protozoaires, plantes et animaux dans tous les écosystèmes de la planète. En connaissant le poids moyen de chaque organisme, les auteurs ont ensuite réalisé des sommes. Ils arrivent au chiffre final de 550 gigatonnes (Gt) de carbone. Ce chiffre est-il élevé ? Avec quoi peut-on le comparer? Est-il précis ? Quels sont les organismes les plus importants dans la biosphère ? Quelles sont les conséquences pour le cycle du carbone, et donc pour la concentration de CO2 atmosphérique ? Voici toute une série de questions que l’on doit se poser. Nous allons voir que les résultats de Yinon Bar-On sont assez étonnants et qu’ils induisent des conséquences majeures pour le cycle du carbone dans la biosphère.

 

Figure 1. Biomasse totale de la biosphère, en gigatonnes (Gt). Bar-On et al. (2018)

‘Glimmer Of Hope’ For Great Barrier Reef As Study Shows Tolerance To Climate Change

by Nick Visser, December 10, 2018 in Huffpost


Last year’s oceanic heat wave wasn’t as destructive as one the year before, scientists said.

The Great Barrier Reef fared better during an oceanic heat wave last year than during sizzling weather a year earlier that caused hundreds of miles of corals to bleach, according to a study published Monday that suggests the massive structure may be growing more tolerant to climate change.

The report in the journal Nature Climate Change analyzed how corals along the Great Barrier fared in back-to-back mass bleaching events. The reef ― a UNESCO World Heritage Site and the largest living structure on the planet ― was cooked by overheated seawater in 2016 and again in 2017, with images of sickly white coral horrifying people around the globe.

See also here

A Brachiopod’s Twelve-Decade Response to Ocean Acidification and Warming

by Cross et al., November 29, 2018 in CO2Science


Paper Reviewed
Cross, E.L., Harper, E.M. and Peck, L.S. 2018. A 120-year record of resilience to environmental change in brachiopods. Global Change Biology 24: 2262-2271.

In light of all their findings, Cross et al. conclude that “these rhynchonelliform brachiopods have therefore been unaffected in their abilities to construct and maintain their extensive skeletons by the change in ocean acidity and temperature over the last 120 years.” And this is a noteworthy conclusion, given that C. inconspicua is one of the most calcium-carbonate-dependent species globally, and is therefore presumed to be highly susceptible to ocean acidification. It would thus appear that proper incorporation of species’ adaptation and/or acclimation potentials is essential if scientists are to get predictions of the impacts of ocean acidification on marine life correct.

Thriving reef fisheries continue to provide food despite coral bleaching

by Lancaster University, November 29, 2018 in ScienceDaily/Nature


The unexpected results of a 20-year study into reef fisheries published in the journal Nature Ecology and Evolution this week showed fisheries being maintained despite extreme coral bleaching. Remarkably, rapid proliferation of fishes with low dependence on corals led to catches remaining stable or even increasing.

But the results also showed fishing success was ‘patchy’ and more dependent on fewer species.

Around six million people fish on coral reefs. Each year their catch — estimated to be between 1.4 and 4.2 million tonnes — provides a critical source of food and income for many millions more.